Panmictic structure of<i>Helicobacter pylori</i>demonstrated by the comparative study of six genetic markers

Salaün, Laurence; Audibert, Céline; Lay, G. Le; Burucoa, Christophe; Fauchère, Jean-Louis; Picard, Bertrand

doi:10.1111/j.1574-6968.1998.tb12953.x

Cited by 28 publications

(5 citation statements)

References 35 publications

(46 reference statements)

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“…Results obtained by Salaün et al [66] using six genetic markers to study genome variation in several isolates support the hypothesis of a panmictic structure for the H. pylori species [52]. In our study, the high level of genetic polymorphism seen with the HaeIII ribopatterns, DraI (GTG) 5 This may give a survival advantage to one of the strains, which will become the dominant strain.…”

Section: Genome Variationsupporting

confidence: 86%

Rapid genomic diversification ofHelicobacter pylori

et al. 1999

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Section: Genome Variationsupporting

confidence: 86%

Rapid genomic diversification ofHelicobacter pylori

et al. 1999

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“…H. pylori has long been characterized as panmictic (Salaun et al, 1998), and as with other bacterial species, the ability of H. pylori to alter its genetic make-up likely allows the bacterium to adapt to the host environment and establish persistent infection. Indeed, the host appears to impose a selective pressure that drives variation within the bacterium (Thompson et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

Analysis of a single Helicobacter pylori strain over a 10-year period in a primate model

Liu

Fero

Mendez

et al. 2015

International Journal of Medical Microbiology

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Helicobacter pylori from different individuals exhibits substantial genetic diversity. However, the kinetics of bacterial diversification after infection with a single strain is poorly understood. We investigated evolution of H. pylori following long-term infection in the primate stomach; Rhesus macaques were infected with H. pylori strain USU101 and then followed for 10 years. H. pylori was regularly cultured from biopsies, and single colony isolates were analyzed. At 1-year, DNA fingerprinting showed that all output isolates were identical to the input strain; however, at 5-years, different H. pylori fingerprints were observed. Microarray-based comparative genomic hybridization revealed that long term persistence of USU101 in the macaque stomach was associated with specific whole gene changes. Further detailed investigation showed that levels of the BabA protein were dramatically reduced within weeks of infection. The molecular mechanisms behind this reduction were shown to include phase variation and gene loss via intragenomic rearrangement, suggesting strong selective pressure against BabA expression in the macaque model. Notably, although there is apparently strong selective pressure against babA, babA is required for establishment of infection in this model as stains in which babA was deleted were unable to colonize experimentally infected macaques.

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“…It is now clear that homologous recombination in microbial populations is often a major source of genome diversity. Analyses of large data sets from closely related microorganisms have often revealed panmictic populations in which a high rate of homologous recombination has caused a random association between loci: for example, Helicobacter pylori (Salaün et al 1998); Halorubrum spp. (Papke et al 2004); and Burkholderia pseudomallei (Pearson et al 2009).…”

Section: Introductionmentioning

confidence: 99%

Quantifying Homologous Replacement of Loci between Haloarchaeal Species

Williams

Gogarten

Papke

2012

Genome Biology and Evolution

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In vitro studies of the haloarchaeal genus Haloferax have demonstrated their ability to frequently exchange DNA between species, whereas rates of homologous recombination estimated from natural populations in the genus Halorubrum are high enough to maintain random association of alleles between five loci. To quantify the effects of gene transfer and recombination of commonly held (relaxed core) genes during the evolution of the class Halobacteria (haloarchaea), we reconstructed the history of 21 genomes representing all major groups. Using a novel algorithm and a concatenated ribosomal protein phylogeny as a reference, we created a directed horizontal genetic transfer (HGT) network of contemporary and ancestral genomes. Gene order analysis revealed that 90% of testable HGTs were by direct homologous replacement, rather than nonhomologous integration followed by a loss. Network analysis revealed an inverse log-linear relationship between HGT frequency and ribosomal protein evolutionary distance that is maintained across the deepest divergences in Halobacteria. We use this mathematical relationship to estimate the total transfers and amino acid substitutions delivered by HGTs in each genome, providing a measure of chimerism. For the relaxed core genes of each genome, we conservatively estimate that 11–20% of their evolution occurred in other haloarchaea. Our findings are unexpected, because the transfer and homologous recombination of relaxed core genes between members of the class Halobacteria disrupts the coevolution of genes; however, the generation of new combinations of divergent but functionally related genes may lead to adaptive phenotypes not available through cumulative mutations and recombination within a single population.

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Panmictic structure ofHelicobacter pyloridemonstrated by the comparative study of six genetic markers

Cited by 28 publications

References 35 publications

Rapid genomic diversification ofHelicobacter pylori

Rapid genomic diversification ofHelicobacter pylori

Analysis of a single Helicobacter pylori strain over a 10-year period in a primate model

Quantifying Homologous Replacement of Loci between Haloarchaeal Species

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